"""
Simple example for a user-defined service.
"""

from core.services.coreservices import CoreService, ServiceMode


class MyService(CoreService):
    """
    Custom CORE Service

    :var str name: name used as a unique ID for this service and is required, no spaces
    :var str group: allows you to group services within the GUI under a common name
    :var tuple executables: executables this service depends on to function, if executable is
        not on the path, service will not be loaded
    :var tuple dependencies: services that this service depends on for startup, tuple of service names
    :var tuple dirs: directories that this service will create within a node
    :var tuple configs: files that this service will generate, without a full path this file goes in
        the node's directory e.g. /tmp/pycore.12345/n1.conf/myfile
    :var tuple startup: commands used to start this service, any non-zero exit code will cause a failure
    :var tuple validate: commands used to validate that a service was started, any non-zero exit code
        will cause a failure
    :var ServiceMode validation_mode: validation mode, used to determine startup success.
        NON_BLOCKING    - runs startup commands, and validates success with validation commands
        BLOCKING        - runs startup commands, and validates success with the startup commands themselves
        TIMER           - runs startup commands, and validates success by waiting for "validation_timer" alone
    :var int validation_timer: time in seconds for a service to wait for validation, before determining
        success in TIMER/NON_BLOCKING modes.
    :var float validation_validation_period: period in seconds to wait before retrying validation,
        only used in NON_BLOCKING mode
    :var tuple shutdown: shutdown commands to stop this service
    """

    name = "MyService"
    group = "Utility"
    executables = ()
    dependencies = ()
    dirs = ()
    configs = ("myservice1.sh", "myservice2.sh")
    startup = ("sh %s" % configs[0], "sh %s" % configs[1])
    validate = ()
    validation_mode = ServiceMode.NON_BLOCKING
    validation_timer = 5
    validation_period = 0.5
    shutdown = ()

    @classmethod
    def on_load(cls):
        """
        Provides a way to run some arbitrary logic when the service is loaded, possibly to help facilitate
        dynamic settings for the environment.

        :return: nothing
        """
        pass

    @classmethod
    def get_configs(cls, node):
        """
        Provides a way to dynamically generate the config files from the node a service will run.
        Defaults to the class definition and can be left out entirely if not needed.

        :param node: core node that the service is being ran on
        :return: tuple of config files to create
        """
        return cls.configs

    @classmethod
    def generate_config(cls, node, filename):
        """
        Returns a string representation for a file, given the node the service is starting on the config filename
        that this information will be used for. This must be defined, if "configs" are defined.

        :param node: core node that the service is being ran on
        :param str filename: configuration file to generate
        :return: configuration file content
        :rtype: str
        """
        cfg = "#!/bin/sh\n"

        if filename == cls.configs[0]:
            cfg += "# auto-generated by MyService (sample.py)\n"
            for ifc in node.netifs():
                cfg += 'echo "Node %s has interface %s"\n' % (node.name, ifc.name)
        elif filename == cls.configs[1]:
            cfg += "echo hello"

        return cfg

    @classmethod
    def get_startup(cls, node):
        """
        Provides a way to dynamically generate the startup commands from the node a service will run.
        Defaults to the class definition and can be left out entirely if not needed.

        :param node: core node that the service is being ran on
        :return: tuple of startup commands to run
        """
        return cls.startup

    @classmethod
    def get_validate(cls, node):
        """
        Provides a way to dynamically generate the validate commands from the node a service will run.
        Defaults to the class definition and can be left out entirely if not needed.

        :param node: core node that the service is being ran on
        :return: tuple of commands to validate service startup with
        """
        return cls.validate
